Outcomes after redo aortobifemoral bypass for aortoiliac occlusive disease.

OBJECTIVE: Patients presenting with occluded aortobifemoral (ABF) bypass grafts are managed with a variety of techniques. Redo ABF (rABF) bypass procedures are infrequently performed because of concerns about procedural complexity and morbidity. The purpose of this analysis was to compare midterm results of rABF bypass with those of primary ABF (pABF) bypass for aortoiliac occlusive disease to determine if there are significant differences in outcomes. METHODS: A retrospective review was performed of all patients undergoing ABF bypass for occlusive disease between January 2002 and March 2012. A total of 19 patients underwent rABF bypass and 194 received pABF bypass during that period. Data for an indication- and comorbidity-matched case-control cohort of 19 elective pABF bypass patients were collected for comparison to the rABF bypass group. Primary end points included rate of major complications as well as 30-day and all-cause mortality. Secondary end points were amputation-free survival and freedom from major adverse limb events. RESULTS: The rABF bypass patients more frequently underwent prior extra-anatomic or lower extremity bypass operations compared with pABF bypass patients (P = .02); however, no difference was found in the incidence of prior failed endovascular iliac intervention (P = .4). By design, indications for the rABF and pABF bypass groups were the same (claudication, n = 6/6 [31.6%]; P = 1; critical limb ischemia, n = 13/13 [78.4%]; P = 1). Aortic access was more frequently by retroperitoneal exposure in the rABF bypass group (n = 13 vs n = 1; P < .0001), and a significantly higher proportion of the rABF bypass patients required concomitant infrainguinal bypass or intraprocedural adjuncts such as profundaplasty (n = 14 vs n = 5; P = .01). The rABF bypass patients experienced greater blood loss (1097 ± 983 mL vs 580 ± 457 mL; P = .02), received more intraoperative fluids (3400 ± 1422 mL vs 2279 ± 993 mL; P = .01), and had longer overall procedure times (408 ± 102 minutes vs 270 ± 48 minutes; P < .0001). Length of stay (days ± standard deviation) was similar (pABF bypass, 11.2 ± 10.4; rABF bypass, 9.1 ± 4.5; P = .7), and no 30-day or in-hospital deaths occurred in either group. Similar rates of major complications occurred in the two groups (pABF bypass, n = 6 [31.6%]; rABF bypass, n = 4 [21.1%]; observed difference, 9.5%; 95% confidence interval, -17.6% to 36.7%; P = .7). Two-year freedom from major adverse limb events (±standard error mean) was 82% ± 9% vs 78% ± 10% for pABF and rABF bypass patients (log-rank, P = .6). Two-year amputation-free survival was 90 ± 9% vs 89 ± 8% between pABF and rABF bypass patients (P = .5). Two-year survival was 91% ± 9% and 90% ± 9% for pABF and rABF bypass patients (P = .8). CONCLUSIONS: Patients undergoing rABF bypass have higher procedural complexity compared with pABF bypass as evidenced by greater operative time, blood loss, and need for adjunctive procedures. However, similar perioperative morbidity, mortality, and midterm survival occurred in comparison to pABF bypass patients. These results support a role for rABF bypass in selected patients.

Defining utility and predicting outcome of cadaveric lower extremity bypass grafts in patients with critical limb ischemia.

OBJECTIVE: Despite poor long-term patency, acceptable limb salvage has been reported with cryopreserved saphenous vein bypass (CVB) for various indications. However, utility of CVB in patients with critical limb ischemia (CLI) remains undefined. The purpose of this analysis was to determine the role of CVB in CLI patients and to identify predictors of successful outcomes. METHODS: A retrospective review of all lower extremity bypass (LEB) procedures at a single institution was completed, and CVB in CLI patients were further analyzed. The primary end point was amputation-free survival. Secondary end points included primary patency and limb salvage. Life tables were used to estimate occurrence of end points. Cox regression analysis was used to determine predictors of limb salvage. RESULTS: From 2000 to 2012, 1059 patients underwent LEB for various indications, of whom 81 received CVB for either ischemic rest pain or tissue loss. Mean age (± standard deviation) was 66 ± 10 years (male, 51%; diabetes, 51%; hemodialysis dependence, 12%), and 73% (n = 59) had history of failed ipsilateral LEB or endovascular intervention. None had sufficient autogenous conduit for even composite vein bypass. Infrainguinal CVB (infrapopliteal target, 96%; n = 78) was completed for multiple indications including Rutherford class 4 (42%; n = 34), class 5 (40%; n = 32), and class 6 (18%; n = 15). Eleven (14%) had CLI and concomitant graft infection (n = 8) or acute on chronic ischemia (n = 3). Intraoperative adjuncts (eg, profundaplasty, suprainguinal stent or bypass) were completed in 49% (n = 40) of cases. Complications occurred in 36% (n = 29), with 30-day mortality of 4% (n = 3). Median follow-up for CLI patients was 11.8 (interquartile range, 0.4-28.4) months with corresponding 1- and 3-year actuarial estimated survival (± standard error mean) of 84% ± 4% and 62% ± 6%. Primary patency of CVB for CLI was 27% ± 6% and 17% ± 6% at 1 and 3 years, respectively. Amputation-free survival was 43% ± 6% and 23% ± 6% at 1 and 3 years, respectively, and significantly higher for rest pain (59% ± 9%, 36% ± 10%) compared with tissue loss (31% ± 7%, 14% ± 7%; log-rank, P = .04). Freedom from major amputation after CVB for CLI was 57% ± 6% and 43% ± 7% at 1 and 3 years. Multivariable predictors of limb salvage for the CVB CLI cohort included postoperative warfarin (hazard ratio [HR], 0.4; 95% confidence interval [CI], 0.2-0.8), dyslipidemia (HR, 0.4; 95% CI, 0.2-0.9), and rest pain (HR, 0.4; 95% CI, 0.2-0.9). Predictors of major amputation included graft infection (HR, 3.1; 95% CI, 1.1-9.0). CONCLUSIONS: In CLI patients with no autologous conduit and prior failed infrainguinal bypass, CVB outcomes are disappointing. CVB performs best in patients with rest pain, particularly those who can be anticoagulated with warfarin. However, it may be an acceptable option in patients with minor tissue loss or concurrent graft infection, but consideration should be weighed against the known natural history of nonrevascularized CLI and nonbiologic conduit alternatives, given potential cost implications.

Critical analysis of results after chimney endovascular aortic aneurysm repair raises cause for concern.

OBJECTIVE: "Chimney" techniques used to extend landing zones for endovascular aortic repair (chEVAR) have been increasingly reported; however, concerns about durability and patency remain. The purpose of this analysis was to examine midterm outcomes of chEVAR. METHODS: All patients at the University of Florida treated with chEVAR were reviewed. Major adverse events (MAEs) were recorded and defined as any chimney stent thrombosis, type Ia endoleak in follow-up, reintervention, 30-day/in-hospital death, or ≥25% decrease in estimated glomerular filtration rate after discharge. Primary end points included chimney stent patency and freedom from MAE. Secondary end points included complications and long-term survival. RESULTS: From 2008 to 2012, 41 patients (age ± standard deviation, 73 ± 8 years; male, 66% [n = 27]) were treated with a total of 76 chimney stents (renal, n = 51; superior mesenteric artery, n = 16; celiac artery, n = 9) for a variety of indications: juxtarenal, 42% (n = 17, one rupture), suprarenal, 17% (n = 7), and thoracoabdominal aneurysm, 17% (n = 7); aortic anastomotic pseudoaneurysm, 15% (n = 6; three ruptures); type Ia endoleak after EVAR, 7% (n = 3); and atheromatous disease, 2% (n = 1). Two patients had a single target vessel abandoned because of cannulation failure, and one had a type Ia endoleak at case completion (technical success, 93%). Intraoperative complications occurred in seven patients (17%), including graft maldeployment with unplanned mesenteric chimney (n = 2) and access vessel injury requiring repair (n = 5). Major postoperative complications developed in 20% (n = 8). The 30-day mortality and in-hospital mortality were 5% (n = 2) and 7% (n = 3), respectively. At median follow-up of 18.2 months (range, 1.4-41.5 months), 28 of 33 patients (85%) with available postoperative imaging experienced stabilization or reduction of abdominal aortic aneurysm sac diameters. Nine patients (32%) developed endoleak at some point during follow-up (type Ia, 7% [n = 3]; type II, 10% [n = 4]; indeterminate, 7% [n = 3]), and one patient underwent open, surgical conversion. The estimated probability of freedom from reintervention (±standard error mean) was 96% ± 4% at both 1 year and 3 years. Primary patency of all chimney stents was 88% ± 5% and 85% ± 5% at 1 year and 3 years, respectively. Corresponding freedom from MAEs was 83% ± 7% and 57% ± 10% at 1 year and 3 years. The actuarial estimated survival for all patients at 1 year and 5 years was 85% ± 6% and 65% ± 8%, respectively. CONCLUSIONS: These results demonstrate that chEVAR can be completed with a high degree of success; however, perioperative complications and MAEs during follow-up, including loss of chimney patency and endoleak, may occur at a higher rate than previously reported. Elective use of chEVAR should be performed with caution, and comparison to open and fenestrated EVAR is needed to determine long-term efficacy of this technique.

Elective endovascular aortic repair conversion for type Ia endoleak is not associated with increased morbidity or mortality compared with primary juxtarenal aneurysm repair.

OBJECTIVE: Type Ia endoleak after endovascular aortic repair (EVAR) can be a challenging complication to manage, and due to concerns regarding morbidity and mortality of open surgical conversion (OSC), reports of complex endoluminal salvage techniques are increasing. Despite development of these endovascular remedial strategies, many patients ultimately require OSC. The purpose of this analysis was to outcomes of elective OSC for type Ia endoleak and compare them with elective primary open juxtarenal aneurysm repair (OJAR) to determine if these concerns are warranted. METHODS: From 2000 to 2012, 54 patients underwent EVAR OSC at median time of 27 months (interquartile range, 9-55 months). Indications included endograft thrombosis in 2 (4%), intraoperative EVAR failure in 3 (6%), rupture in 5 (9%), graft infection in 6 (11%), and type Ia endoleak in 25 (all: 38 [70%]). Because many OSCs are performed for emergency indications without endovascular options, we chose elective type Ia endoleak patients as our study group. These 25 patients were compared with an elective OJAR cohort matched by anatomy and comorbidities. Primary end points were 30-day and 1-year mortality. Secondary end points included early complications, cross-clamp time, procedure time, blood loss, and length of stay. RESULTS: Demographic and comorbidity data in the OSC and OJAR groups did not differ, with the exception that OJAR patients presented with smaller aneurysm diameter and a higher rate of chronic obstructive pulmonary disease (P = .03). OSC patients more frequently underwent a nontube graft repair (OSC, n = 20 [80%] vs OJAR, n = 6 [24%]; P = .0002), required longer procedure times (P = .03), and received more plasma transfusions (P = .03). The 30-day mortality was 4% in both groups (observed difference in rates, 0%; 95% confidence interval for difference in mortality rates, -14.0% to 14.0%; P = 1). A similar rate of major complications occurred (OSC, n = 9 [36%] vs OJAR, n = 8 [32%]; P = 1). One-year survival was 83% in OSC and 91% in OJAR (observed difference, 7%; 95% confidence interval, -15% to 29%; P = .65). CONCLUSIONS: Despite many advances in EVAR technology, the need for OSC persists and will likely become more common as older-generation devices fail or providers attempt EVAR in more anatomically complex patients. Elective OSC for type Ia endoleak can be technically challenging but is not associated with increased morbidity or mortality compared with OJAR in appropriately selected patients. These results should be considered before pursuing complex endovascular remediation of EVAR failures.

Treatment of acute visceral aortic pathology with fenestrated/branched endovascular repair in high-surgical-risk patients.

OBJECTIVE: The safety and feasibility of fenestrated/branched endovascular repair of acute visceral aortic disease in high-risk patients is unknown. The purpose of this report is to describe our experience with surgeon-modified endovascular aneurysm repair (sm-EVAR) for the urgent or emergent treatment of pathology involving the branched segment of the aorta in patients deemed to have prohibitively high medical and/or anatomic risk for open repair. METHODS: A retrospective review was performed on all patients treated with sm-EVAR for acute indications. Planning was based on three-dimensional computed tomographic angiogram reconstructions and graft configurations included various combinations of branch, fenestration, or scallop modifications. RESULTS: Sixteen patients (mean age [± standard deviation], 68 ± 10 years; 88% male) deemed high risk for open repair underwent urgent or emergent repair using sm-EVAR. Indications included degenerative suprarenal or thoracoabdominal aneurysm (six), presumed or known mycotic aneurysm (four), anastomotic pseudoaneurysm (three), false lumen rupture of type B dissection (two), and penetrating aortic ulceration (one). Nine (56%) had previous aortic surgery and all patients were either American Society of Anesthesiologists class IV (n = 9) or IV-E (n = 7). A total of 40 visceral vessels (celiac, 10; superior mesenteric artery, 10; right renal artery, 10; left renal artery, 10) were revascularized with a combination of fenestrations (33), directional graft branches (six), and graft scallops (one). Technical success was 94% (n = 15/16), with one open conversion. Median contrast use was 126 mL (range, 41-245) and fluoroscopy time was 70 minutes (range, 18-200). Endoleaks were identified intraoperatively in four patients (type II, n = 3; type IV, n = 1), but none have required remediation. Mean length of stay was 12 ± 15 days (median, 5.5; range, 3-59). Single complications occurred in five (31%) patients as follows: brachial sheath hematoma (one), stroke (one), ileus (one), respiratory failure (one), and renal failure (one). An additional patient experienced multiple complications including spinal cord ischemia (one) and multiorgan failure resulting in death (n = 1; in-hospital mortality, 6.3%). The majority of patients were discharged to home (63%; n = 10) or short-term rehabilitation units (25%; n = 4), while one patient required admission to a long-term acute care setting. There were no reinterventions at a median follow-up of 6.2 (range, 1-16.1) months. Postoperative computed tomographic angiogram was available for all patients and demonstrated 100% branch vessel patency, with one type III endoleak pending intervention. There were two late deaths at 1.4 and 13.4 months due to nonaortic-related pathology. CONCLUSIONS: Urgent or emergent treatment of acute pathology involving the visceral aortic segment with fenestrated/branched endograft repair is feasible and safe in selected high-risk patients; however, the durability of these repairs is yet to be determined.

Endovascular treatment of acute and chronic aortic pathology in patients with Marfan syndrome.

BACKGROUND: In patients with Marfan syndrome, the complications of aortic degeneration, including dissection, aneurysm, and rupture represent the main cause of mortality. Although contemporary management of ascending aortic disease requires open surgical reconstruction, endovascular repair is now available for management of descending thoracic and abdominal aortic pathology (ie, thoracic endovascular aortic repair [TEVAR], endovascular aneurysm repair [EVAR]). The short- and long-term benefit of endovascular repair in Marfan patients remains largely unproven. We examine our outcomes after EVAR in this patient population. METHODS: All patients with a diagnosis of Marfan syndrome who were treated with TEVAR/EVAR were evaluated in a retrospective review. Perioperative, procedure-specific and patient covariate data were aggregated. Primary endpoints were overall mortality and procedural success as divided into three categories: (1) successful therapy, (2) primary failure, or (3) secondary failure. RESULTS: Between 2000 and June 2010, 16 patients were identified as having undergone 19 TEVAR/EVAR procedures. These included three emergent operations (two for acute dissection/malperfusion and one for anastomotic disruption early after open repair). All 16 patients had previously undergone at least one (range, 1-5) open operation of the ascending aorta or arch at a time interval from 33 years to 1 week prior to the index endovascular repair. During a median follow-up of 9.3 months (range, 0-46 months), there were four deaths (25%). Six patients (38%) had successful endovascular interventions. Despite early success, there was one death in this group at 1 month postintervention. Seven patients (44%) experienced primary treatment failure with five undergoing open conversion and one undergoing left subclavian coil embolization (the seventh was lost to follow-up and presented 4 months later in cardiac arrest and expired without repair). There were three deaths in the primary treatment failure group. Two patients experienced secondary treatment failure. One underwent the index TEVAR for acute dissection with malperfusion and required a subsequent TEVAR for more distal aortic pathology. He is stable without disease progression. The other patient underwent open conversion after a second EVAR with four-vessel "chimney" stent grafts and is stable with his entire native aorta having been replaced. CONCLUSIONS: Aortic disease associated with Marfan syndrome is a complex clinical problem and many patients require remedial procedures. Endovascular therapy can provide a useful adjunct or bridge to open surgical treatment in selected patients. However, failure of endovascular therapy is common, and its use should be judicious with close follow-up to avoid delay if open surgical repair is required.

Is endoscopic resection of gastric gastrointestinal stromal tumors safe?

Gastric gastrointestinal stromal tumors (GIST) commonly present as an incidental finding on upper gastrointestinal endoscopy. Advances in endoscopic technology have allowed some to perform attempted excision of these lesions endoscopically. The oncologic implications of such an approach remain unclear. A-74-year-old man initially presented with an incidental finding of a 1.6 x 1.8-cm c-kit-positive gastrointestinal stromal tumor with low mitotic activity in the gastric fundus. The patient underwent an attempted endoscopic resection of this mass resulting in incomplete excision and gastric perforation. There was immediate conversion to a celiotomy and the patient underwent partial gastrectomy; there was no evidence of metastatic GIST. Three years later, the patient was noted to have an asymptomatic large pelvic mass (4 x 7 cm) on CT scan and was referred for evaluation. Subsequent surgical exploration revealed a single mass adherent to the pelvic sidewall that was resected. Subsequent pathology demonstrated a c-kit-positive GIST consistent with metastatic disease. Eighteen months later, the patient remains free of disease. Complications from endoscopic resection of gastric GIST may be associated with peritoneal dissemination of disease. This should be considered when formulating a strategy for management of gastric GIST. Complete transperitoneal excision (either open or laparoscopic) with clear margins and without tumor rupture remains the gold standard for management of gastric GIST.

Comprehensive solid-phase extraction method for persistent organic pollutants. Validation and application to the analysis of persistent chlorinated pesticides.

The Centers for Disease Control and Prevention (CDC) is involved in many epidemiological studies regarding the measurement of chlorinated pesticides and polychlorinated biphenyls in specimens obtained from humans. In addition to these commonly determined analytes, there is a need to include additional persistent organic pollutants (POPs) in our analyses, which further stresses the analyses because sample volumes remain small. Thus, a single method of analysis for all POPs in human serum is needed. CDC has recently developed a semiautomated and comprehensive solid-phase extraction method for POPs. The method is comprehensive since it was optimized for the extraction of many different POP compound classes. We then developed a purification and fractionation scheme that allows (a) separation of different compound classes by particular functionalities and (b) purification of those fractions to remove coextracted interferences. This paper describes the first step in the semiautomated comprehensive extraction and multiple fractionation method developed by CDC for monitoring POPs. In this paper, we validate the analysis of the persistent chlorinated pesticides, a compound class difficult to examine because of their structural diversity, in human plasma. The method was validated against an existing CDC method by using a spiked quality-control serum pool. The concentrations determined for all analytes using both methods were within 2%-14% relative standard deviations. A multilevel (i.e., 3-4 point) matrix spike showed good linearity for the analytes tested (r2 = 0.978-0.999). The method was then applied to 40-year-old archived plasma samples for the quantitative analysis of selected chlorinated pesticides. Mean recoveries of the 13C-labeled internal quantification standards ranged from 64% to 123% for the 11 monitored pesticides. The overall method proved to be robust by handling old coagulated plasma samples. It allowed faster throughput of samples than our previous methods and provided cleaner samples with less frequent interferences or background as analyzed by high-resolution mass spectrometry. The method represents a preliminary step in establishing an automated, comprehensive multiresidue analysis method for POPs in human serum.